A multiple-input and multiple-output (MIMO) communication system is a communication system that is capable of transmitting and receiving data between end user equipment and network equipment using multiple antennas in both the end user equipment and the network equipment. The network equipment and the end user equipment both have multiple antennas. The use of multiple antennas may improve the efficiency in transferring information between the end user equipment and the network equipment. A multiple-input and multiple-output communication system is capable of transmitting information between the network equipment and the end user equipment using the antennas.
The transmission rate of information may be improved by a special division multiple access scheme. This type of scheme may allocate spatial beams to the end user equipment for transmitting data to the network equipment using the spatial beams. The allocation of these beams may be referred to as precoding. Precoding is performed using a matrix, which may be referred to as a codeword. A code book containing multiple codewords is present in the end user equipment.
This precoding process may involve the network equipment being aware of the properties of the communication channel used with the user equipment. The network equipment may send information or instructions to the user equipment for the selection of a particular codeword in the code book for use in transmitting information.
Generating code books that increase performance may be challenging when sending information from end user equipment to network equipment. The size of code books may be limited, depending on the user equipment. Further, the complexity of code books may reduce performance.
Therefore, it would be advantageous to have a method and apparatus that takes into account at least some of the issues discussed above, as well as possibly other issues.